Total Guide to Drill Chucks and Holding Twist Drills

Last modified: June 18, 2024

Introduction

Twist Drills are the most common cutter type in the CNC arsenal, and they're most commonly held in the machine tool via a drill chuck.  They can also be held in an ER collet chuck and by various other methods.  In this article, we'll go through all this and show you how to get the best performance from your tool holding solution when it comes to twist drills.

Drill Chuck Types

There are commonly two types of drill chucks-Jacobs Chucks and Keyless Drill Chucks.

Jacobs Chuck (Chuck Key Style)

Jacobs chucks are called that because they use a Jacobs Taper.

Jacobs chucks require a key to operate:

Small metal tool with T-shaped handle and threaded end.

Keyless Drill Chuck (Albrecht)

Keyless Drill Chucks were invented in 1908 by the firm Albrecht, and are often referred to as Albrecht chucks.  They're often preferred to Jacobs chucks because no key or wrench is needed.  A simple twist of the body tightens the chuck firmly:

Metal drill bit with twisted gold tip on a white background.

Drill Chuck Sizes

Keyed drill chucks on a wooden base.

Image courtesy of micro-machine-shop...

Drill chucks come in a great variety of sizes from small to large.

Jacobs Chuck Sizes

Ball bearing taper mounts with specifications and features.

Courtesy of Jacobs...

Keyless Chuck Sizes

Albrecht Classic Precision Keyless Drill Chuck specifications table with illustration.

Keyless Drill Chuck Sizes, courtesy of Royal Products...

Mini Drill Chucks, Pin Chucks, and Sensitive Drill Feeds

When drilling small holes, sometimes special chucks and accessories may be required.

The sensitive drill feed is an arbor with spring-loaded extension that can be used to hand feed delicate small twist drills with a smaller chuck:

Cylindrical metal object with threaded end and flat base.

Sensitive Feeds are useful on manual mills and drill presses, but are seldom used with CNC where exact feeds are easily programmed.

Drill Chucks vs Collet Chucks

Drill Chucks have a number of advantages over collet chucks:

In general, if you have a well-made drill chuck, it should be as accurate as a collet chuck and will be more versatile as well as gripping the twist drill more tightly.

Mount a Drill Chuck to Stay on its Taper

I prefer to shrink fit my chucks onto their tapers.  I put the chuck in the oven at just under 200 degrees and the arbor in the freezer.  After 10-15 minutes, tap them sharply together.  The temperature difference ensures a tighter fit.

Remove a Drill Chuck

If your drill chuck is mounted on a machine taper, then you'll use a drill chuck removal wedge to remove it:

Gray metal tool with two prongs and close-up photo of a cylindrical object.

The wedge goes between top of chuck and the flange on the taper to force the two apart.  [Instructables has a good article on how to appro](https://ach i)ach iit.

Make sure your chuck isn't threaded on, as a wedge will damage a threaded drill chuck installation.

Handy Chuck Key Holder

It's hard to see in this photo, but I use a triangular welder's magnet to hold my chuck key to my drill press so it's always there:

Green metal drilling press with red switch, silver shaft, and black knob against a white wall background.

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